The Flow Cytometry Core provides a broad range of applications to Cancer Center Members including the following: light scatter measurements assessing cell volume and structural differences; single and multiple intracellular and/or surface immunofluorescence measurements; DNA ploidy measurements of cellular calcium and potassium flux, and oxidative burst; detection and quantitation of apoptotic cell death; cell sorting on any or a combination of several analytical criteria. The Flow Cytometry Core Facility re-located in the University of Michigan Cancer and Geriatrics Center's building upon completion of the new facility in 1997. Members of the UMCCC (108 users in 1999) constitute a majority of the use of the Core, and the UMCCC provides 39% of the operating budget of the facility ($253,000 in 1999). In return for this support, UWCCC members are eligible for a 50% discounted recharge rate. Individual investigators deliver pre-processed samples to the Core for flow cytometric analyses or cell sorting. Scheduling for Core access typically requires a lead-time of 24 hours notice. The Core is available to investigators from 8:00 AM to 6:00 PM, Monday through Friday, and from 8:00 to 1:00 Saturday. Core instrumentation includes two Beck-Coulter Elite ESP multi-laser cell sorters, a Becton Dickinson FACS Vantage SE multi-laser high-speed cell sorter, and a Coulter EPICS XL analyzer.